Looked into imprinting by dividing goose eggs to have their mother as himself (hatched in an incubator) or their biological mother (hatched in their natural environment)
Both groups grew up following their 'mother' and even when mixed up they still then followed their conditioned 'mother'
Identified the critical period for where the babies will attach to the first moving thing, they see which was the mother goose or Lorenz, if they didn't attach during this period they didn't have a mother figure
Looked into sexual imprinting where he hatched a peacock in a zoo where it saw a giant tortoise first, as an adult it would only show courtship towards giant tortoises
Used monkeys to look into the idea of importance of comfort
Babies that were left alone often died, so he set up 16 baby monkeys with 2 wires 'mothers' that dispensed milk, one covered in cloth
Found that the monkeys would cuddle the cloth 'mother' for comfort and not the wire mother regardless of the circumstances or food given showing that comfort was more important than food
Looked to see if early maternal deprivation would have effects in adulthood, finding that they were dysfunctional from the plain wire 'mothers', while the cloth 'mothers' made them abnormal in social situations
Not generalisable due to the difference in species due to their brains being different from humans, making human's behaviour more complex, even though we're closely related
Ethics since his experiment has caused long term damage to the monkeys
Lack of support from animal studies (Harlow and Lorenz showing that there are other factors (not food) that are used in attachment)
Lack of support from human studies (Schaffer and Emerson show that the mother was the PCG regardless of she fed them) making food not the main factor in forming relationships
Babies are only responding to the association with comfort/reward, not any aspect of attachment (Feldman and Edelman)
Around 6 months when the infants attachment system is active, making the child sensitive till around 2 years old, if an attachment isn't formed in this time the child will find it harder to form one later
Support for the role of social releasers (Brazelton states that the innate behaviours are to get the adults attention, when not received they get upset) are important
Bailey supports the IWM with the 99 mothers experiment, measuring the attachment to their own mothers and between the baby (1yr) and mother finding that the relationship was the same